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1.
The properties of the -2-l-fucosyltransferases in submaxillary gland preparations from blood group ABH secrefors and non-secretors were compared. The level of activity in the non-secretor gland homogenates amounted to about 5% only of that found in the secretor gland preparations. The enzymes from the two sources differed in solubility properties, charge and affinities for donor and acceptor substrates. The enzyme from secretor glands showed a preference for acceptors with Type 1 [d-galactosyl(1–3)-N-acetyl-d-glucosamine] structures whereas the enzyme from non-secretor glands had a preference for Type 2 [d-galactosyl(1–4)-N-acetyl-d-glucosamine] structures.These results demonstrate that expression of the secretor gene (Se) is associated with a molecular form of the -2-l-fucosyltransferase that is different from the species present in the same tissue when theSe gene is not expressed.  相似文献   

2.
Different varieties of citrus exhibit a great variation in their susceptibility to infestation by the red scale, Aonidiella aurantii. Among the thirteen varieties investigated, mandarin clemantine, santara and baladi, orange baladi and rough lemon are the most resistant; while lemon baladi, sour orange and grapefruit are the most susceptible. The susceptibility to infestation decreases with the increase of oil glands in the leaves and fruits of citrus. The total amount of nitrogen, phosphorus and carbohydrates in the leaves of different varieties shows no correlation with their susceptibility to infestation.
Résumé Différentes variétés de Citrus montrent de grandes variations dans leur sensibilité aux attaques par Aonidiella aurantii. Parmi les 13 variétés étudiées, les plus résistantes sont: mandarine clémentine, mandarine baladi et rough lemon, tandis que lemon baladi; sour orange et pamplemousse sont les plus sensibles.La sensibilité aux infestations décroît proportionnellement avec l'accroissement du nombre des glandes à huiles essentielles sur les feuilles de citrus. La quantité totale d'azote, de phosphore et d'hydrates de carbone dans les feuilles des différentes variétés ne montre aucune corrélation avec leur sensibilité aux infestations.
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3.
Thermostability of 3-hydroxysteroid dehydrogenase-isomerase (3HSD) activity was examined in testes and adrenal glands from several inbred lines and feral mice. A thermolabile varant of 3HSD was detected in the feral Brno mice. The thermostability (t 1/2) of 3HSD was approximately 7 min for both testes and adrenal glands from C57BL/6J mice, compared with 4 min for both tissues from Brno mice. Comparison of testicular and adrenal 3HSD thermostability in six kinds of mice indicated that the t 1/2of 3HSD was correlated in the two tissues and could be classified into two distinct types, thermolabile and thermostable. In contrast, quantitative variants in 3HSD activity were not correlated in the two tissues. These data are consistent with the hypothesis that testicular and adrenal 3HSD is encoded by the same structural gene but that expression of 3HSD activity is independently controlled in testes and adrenal glands.This work was supported by NICHHD National Research Service Award HD-06392 to J.R.D.S. and Grant HD-17916 to A.H.P.  相似文献   

4.
    
Zusammenfassung Beim wildenPlatypoecilus maculatus aus Mexiko, der im männlichen Geschlecht heterogamet ist (Gordon 1946), ist neben dem gonosomalen noch ein autosomales System von Geschlechtsrealisatoren am Werke (vgl.Öktay 1959). Es vermag in extremen Konstellationen, die zufalls- oder selektionsbedingt sein können, denXY-Mechanismus epistatisch zu überlagern, so da\XY-Individuen zu determiniert werden können.XY- sind voll vital und fertil und ergeben in Paarungen mitXY- nebenXX- undXY- voll vitale und fertileXY-.Auf Grund der vorliegenden Kreuzungsergebnisse und der Befunde anderer Autoren wird angenommen, daß der normalerweise rein gonosomale Geschlechtsbestimmungsmodus vonPlatypoecilus maculatus aus dem primitiveren autosomal polyfaktoriellen, der unter anderem bei einem nahen Verwandten dieser Art,Xiphophorus helleri, vorkommt (Kosswig 1931 ff.), hervorgegangen ist.Mit 1 Textabbildung  相似文献   

5.
Summary Endo--galactosidase from Escherichia freundii cleaves polylactosaminyl structures as follows: R-GlcNAc1-3Gal1-4GlcNAc1-R + H2O R-GlcNAc1–3Gal + GlcNAc1-R. By staining with Griffonia simplicifolia agglutinin-II following the enzyme digestion, the distribution of R-GlcNAc1–3Gal1–4GlcNAc can be demonstrated in tissue sections. This carbohydrate chain is one of the backbone structures carrying the blood-group-related antigens and, thus, localization of this structure may provide detailed information about the distribution of variants with different backbone structures. Various formalin-fixed, paraffin-embedded tissue sections were stained by Griffonia simplicifolia agglutinin-II with or without prior enzyme digestion and the reactivity of the agglutinin imparted by enzyme digestion was studied in the following tissues and cells: pancreatic acinar cells, gastric surface mucosae, duct cells and mucous cells of salivary glands and tracheal glands, surface epithelium of trachea, goblet cells of large intestine, columnar epithelium of uterine cervical glands, distal and collecting tubules of kidney, certain cells of anterior lobe and colloid of middle lobe of pituitary glands, epithelial reticular cells and Hassall's corpuscles of thymus and Kupffer cells of liver. In gastric surface mucosae, the reactivity of the agglutinin appeared in non-secretor individuals but not in the secretor individuals, and in mucous cells of salivary and tracheal glands the reactivity appeared in Le(a - b -) non-secretor individuals but not in Le(a + b -) non-secretor or secretor individuals. In pancreatic acinar cells and duct cells of salivary glands from fetuses and newborn infants, prior fucosidase digestion markedly enhanced the Griffonia simplicifolia agglutinin-II reactivity elicited by endo--galactosidase digestion. Prior fucosidase digestion was also a prerequisite for revealing the reactivity of this agglutinin by endo--galactosidase digestion in gastric surface mucosae from secretor individuals. -Galactosidase digestion disclosed reactivity of this agglutinin in pancreatic acinar cells and duct cells of salivary glands even after the removal of endo--galactosidase-labile lactosamine structures by sequential digestion with endo--galactosidase and -N-acetylhexosaminidase. These results demonstrate that the procedures developed in this study provide a useful means for detecting different types of lactosamine structures which carry blood-group antigens in humans tissues.  相似文献   

6.
Incubation of Chironomus salivary glands with -amanitine in concentrations from 1 to 10 /ml results in the suppression of puffing and chromosomal 3H-uridine incorporation after 30 to 60 min in 80% of the cells. Nucleolar 3H-uridine incorporation remains completely unaffected. Even 4 h after the injection of high doses of -amanitine into living larvae, nucleolar incorporation is still pronounced. The distribution of resistant cells within the salivary glands suggests that the uptake of -amanitine is subject to physiological restrictions.—A puff typically induced during in vitro incubation of salivary glands was found to be less sensitive to -amanitine than the Balbiani rings.  相似文献   

7.
Zeins from Zea mays L cv. Maya and coixins from Coix lacryma-jobi L. cv. Adlay were fractionated to obtain -, -, and -zein and -, -, and -coixin. The -coixins were composed of 4 polypeptide classes of 27 kDa (C1), 25 kDa (C2), 17 kDa (C4) and 15 kDa (C5) with solubility properties very similar to those of the 22 kDa and 19 kDa -zeins. Like the -zeins, the C1 and C2 -coixins corresponded to 80% of total Coix prolamins. The fraction corresponding to -coixin contained only one protein band of 22 kDa (C3). This coixin fraction has solubility properties similar to those of -zein and represents 15% of the total coixin. The -zein fraction was composed of a major 17 kDa protein band, while the -coixin fraction consisted of a mixture of - and -coixins.Polyclonal antibodies raised against C1 recognized C1 and C2 and cross-reacted strongly with the 22 kDa -zein, as did C4 and C5 antisera. The antiserum against -coixin showed strong cross-reaction with -zein. The homology between coixins and zeins was further investigated by using Southern hybridization analyses. The genomic DNA of maize and Coix were digested with several restriction enzymes and probed with cDNA clones representing 19 and 22 kDa -zeins as well as the 28 and 16 kDa -zeins. The Coix genome showed complex cross-hybridization sequences with the 22 kDa -zein cDNA, while no cross-hybridization was observed with the 19 kDa cDNA clone. The cDNA clone representing the 28 kDa -zein cross-hybridized with only one band of Coix genomic DNA, in contrast to the three bands observed in maize. This same Coix sequence also cross-hybridized with the cDNA clone representing the 16 kDa -zein. The relevance of these findings are discussed in the context of the origin of zein and coixin genes.  相似文献   

8.
Summary Candida wickerhamii produces one endocellular and one exocellular -glucosidase. Both enzymes are repressed by glucose in the wild-type strain. In the M7 mutant ofC. wickerhamii, which was previously demonstrated to be derepressed for endocellular -glucosidase biosynthesis, the exocellular -glucosidase is derepressed and hyperproduced when cellodextrins are added to the culture medium. This enzyme, which was produced constitutively in the wildtype, has thus become inducible in the M7 mutant strain. The interest of this strain for industrial production of -glucosidases is discussed.
Resumen Candida wikerhamii produce dos -glucosidasas: una endocelular y otra exocelular. Ambos enzimas son reprimidos por glucosa en la cepa salvaje. Al añadir celodextrina al medio de cultivo del mutante M7 deC. wickerhamii, en el cual se ha demostrado ya la desrepresión de la síntesis de -glucosidasa endocelular, se desreprime la -glucosidasa extracelular obteniéndose una hiperproducción de este enzima. Dicho enzima que era producido de forma constitutiva en el tipo salvaje, se ha convertido en inducible en la cepa mutante M7. Se discute el interés de esta cepa para la producción industrial de -glucosidasas.

Résumé Candida wickerhamii produit deux -glucosidases, l'une endo- et l'autre exocellulaire. Les deux enzymes de la souche sauvage sont réprimées par le glucose. Le mutant M7, chez qui il a été antérieurement constaté que la synthèse de la -glucosidase endocellulaire est déréprimée, l'enzyme exocellulaire est elle aussi déréprimée et hyper-produite lorsque des cellodextrines sont ajoutées au milieu de culture. Cette enzyme, qui est constitutive chez la souche sauvage, est donc devenue inductible chez le mutant M7. Cette souche est intéressante pour la production industrielle de -glucosidases.
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9.
Summary Propionic acidemia is an autosomal recessive metabolic disease resulting from a deficiency of propionyl CoA carboxylase (PCC) activity. We have analyzed the molecular heterogeneity of Japanese propionic acidemia patients using anti-human PCC antiserum and cDNA clones coding for the two protein subunits ( and ) of the enzyme. The steady state levels of both and subunits of PCC from 15 Japanese patients were determined by Western blot. Three patients had neither nor subunits, and the amounts of both and subunits were low in 3 other patients. According to our previous data, we classified these 6 patients as having subunit deficiency. In the remaining 8 patients, subunits were normal, but the subunits were aberrant. Two patients had low levels of normal-sized subunits and 6 had subunits smaller than normal in size and greatly reduced in quantity. These 8 patients were assigned to the subunit deficiency category. One patient had apparently normal and subunits. We could not determine this patient's primary defect. These data reveal the genetic heterogeneity of molecular defects causing propionic acidemia in the Japanese. Southern blot analysis did not reveal any gross alteration in gene structure when DNA was digested withHindIII,EcoRI andTaqI. However, DNA from 3 -subunit-deficient patients, when digested withMspI and probed with PCC cDNA, revealed a unique 2.7-kb band not observed in blots of DNA from any other patient or 15 normal controls. We conclude that this alteredMspI restriction map is the result of a mutation in the subunit gene of these patients.  相似文献   

10.
We study the improvement in timing accuracy in a neural system having n identical input neurons projecting to one target neuron. The n input neurons receive the same stimulus but fire at stochastic times selected from one of four specified probability densities, f, each with standard deviation 1.0 msec. The target cell fires if and when it receives m inputs within a time window of msec. Let n,m, denote the standard deviation of the time of firing of the target neuron (i.e. the standard deviation of the target neuron's latency relative to the arrival time of the stimulus). Mathematical analysis shows that n,m, is a very complicated function of n, m, and . Typically, n,m, is a non-monotone function of m and and the improvement of timing accuracy is highly dependent of the shape of the probability density for the time of firing of the input neurons. For appropriate choices of m, , and f, the standard deviation n,m, may be as low as . Thus, depending on these variables, remarkable improvements in timing accuracy of such a stochastic system may occur.  相似文献   

11.
Summarium Ad oram maritimam arenosam provinciae dictae Vendée, in Gallia Occidentali, septentrionem versus usque ad insulam dictam Noirmoutier, optime crescit Quercus Ilex, silvas efficiens et climacem vegetationis constituens. Cum qua crescunt novem plantae mediterraneae propriae associationi Querceto Ilicis galloprovincialis Br.-Bl., id est quarta pars omnium specierum illi propriarum, et simul nonnullae aliae plantae mediterraneae. Itaque, quamvis dixerit Celeberr. Flahault adesse in Gallia Occidentali nullam associationem Quercus Ilicis, hanc speciem, associationem non similem quidem Querceto Ilicis galloprovincialis, nam speciebus mediterraneis ea pauperiorem et alias plantas atlanticas continentem, at tamen cui proximam, associationem veram, quae dici possit Quercetum Ilicis atlanticum, constituere contra aestimat auctor.Reçu par la rédaction le 7.I.1953.  相似文献   

12.
The genetic control of adult-plant blackleg (Leptosphaeria maculans) resistance in a Brassica napus line (579NO48-109-DG-1589), designated R13 possessing Brassica juncea-like resistance (JR), was elucidated by the analysis of segregation ratios in F2 and F3 populations from a cross between R13 and the highly blackleg-susceptible B. napus cultivar Tower. The F2 segregration ratios were bimodal, demonstrating that blackleg resistance in R13 was controlled by major genes. Analysis of the segregation ratios for 13 F3 families indicated that blackleg resistance in these families was controlled by three nuclear genes, which exhibited a complex interaction. Randomly sampled plants of F3 progeny all had the normal diploid somatic chromosome number for B. napus. The similarities between the action of the three genes found in this study with those controlling blackleg resistance in B. juncea is discussed.  相似文献   

13.
A total of 32 wild Hokkaido sika deer (Cervus nippon yesoensis) were shot (13 in summer, nine in autumn and 10 in winter) in the Syari district, Shiretoko Peninsula of Hokkaido Island, Japan. The ingested foods, rumen fermentation parameters and microbes were determined to evaluate digestive strategy and food availability in each season. Ingested foods and ruminal characteristics greatly varied by season. Rumen digesta mainly comprised of graminoids in summer, graminoids and agricultural products in autumn, and bark and twigs in winter. Rumen pH showed seasonal differences (P<0.05) and was lowest in summer, highest in winter, and intermediate in autumn, reflecting the seasonal differences in ruminal concentration of total volatile fatty acids which were significantly lower (P<0.05) in winter than in summer and autumn. Acetate proportions were significantly higher in winter than in other seasons (P<0.05), while the opposite trend was seen in proportions of propionate and butyrate. Rumen ammonia levels showed significant seasonal differences (P<0.05), decreasing from summer to autumn to winter. Rumen protozoa levels in autumn and winter decreased to 28 and 10% of the levels observed in summer, respectively (P<0.05 for both). The rumen bacteria level in winter was lower (P<0.05) than that in autumn, but no difference was seen for the other seasonal comparisons. Gram negative cocci were present in significantly higher proportions in winter than in other seasons (P<0.05), while Gram negative curved rods were less frequently observed in winter (P<0.05). Based on these results, wild sika deer in this area are shown to survive with rumen microbial populations altered with the dietary conditions that vary greatly by season.  相似文献   

14.
Controlled digestion of 150 kD single chain botulinum type E neurotoxin with pepsin atpH 6.0 produced 112, 48, 46, and 16 kD fragments. These were chromatographically purified; their locations in the 1300 amino acid residue long neurotoxin were determined by identifying the amino terminal 10 residues of 112 and 48 kD fragments, 50 residues of 46 kD fragment, and 59 residues of 16 kD fragment. The 48 and 112 kD fragments contain the N-terminal segment of the neurotoxin (i.e., residue no. 1 to 425 and 1 to 990, respectively), the 46 kD fragment corresponds to 407 residues of the C-terminal region, and the 16 kD fragment contains the 140 residues from a segment nearer to the C-terminus. The 48 kD fragment is similar to the 50 kD N-terminal light chain of the 150 kD dichain neurotoxin, which is generated by tryptic cleavage of the 150 kD single chain neurotoxin, and is separated from the 100 kD C-terminal heavy chain by dithiothreitol (DTT) reduction of an intrachain disulfide bond in the presence of 2 M urea (Sathyamoorthy and DasGupta,J. Biol. Chem. 260, 10461, 1985). The pepsin-generated 48 kD fragment, unlike the light chain, was isolated without exposure to DTT and urea. The single chain 112 kD fragment following trypsin digestion yielded 48 and 60 kD fragments that were separable after DTT reduction of the intrachain disulfide which links them. The N-terminal residues of the smaller fragment were identical to that of the single chain 150 kD neurotoxin; the single chain 112 kD fragment is therefore the neurotoxin minus the 50 kD C-terminal half of the heavy chain. The biological activities of the 48 and 112 kD fragments can be demonstrated in permeabilized PC12 cells (Lomnethet al., J. Neurochem. 57, 1413, 1991); they inhibit norepinephrine release.  相似文献   

15.
A new TA base substitution, identified inside the 5 regulatory region of the humanA globin gene (A –499 T A), is reported. This nucleotide change was found to be linked incis with the mutation producing sickle cell anemia (CD6 GAGGTG: s gene).  相似文献   

16.
Summary Stationary phase cells of strain phr/MC 2 ofE. coli are not photoreactivable but the frequency of UV-induced mutations to low Streptomycine-resistance (S 3, 3/ml) is decreased strongly by illumination with light of fluorescence tubes (310 to 500 nm) after UV-irradiation. Also dark-reversion (DRM) of these mutations due to keeping UV-irradiated cells in saline is observed. Illumination before UV-irradiation decreases the frequency of the mutations (photoprotection against mutation=PPM) to the same extent as the combined action of photoreversion (PRM) and DRM. The lag-phase of cell division is prolonged strongly by illumination from 80 min without light to 150 min by the light-dose of highest activity. The additional lag is nearly the same if the illumination is done before, after or without UV-irradiation; this lag is about additive to the small lag caused by UV. Pre-illumination of the stationary-phase cells does not cause photoprotection against killing (PP), it even decreases the survival after high UV-doses. The observations support the hypothesis that PRM in this strain may be indirect, i.e. caused by the light-induced additional division lag which enhances the dark repair of UV-premutations. Also spontaneous premutations which are apparently present in the stationary-phase cells seem to be influenced by the light in this way.  相似文献   

17.
The localization of -D-galactose, N-acetyl-D-galactosamine, and N-acetyl-D-glucosamine sugar residues of glycoconjugates in the vomeronasal organ, olfactory mucosa, and septal organ in the nasal mucosae of rats was investigated using lectinohistochemical techniques combined with bright-field, epifluorescence, and confocal laser scanning microscopy. Glycoconjugates in the mucomicrovillar complex of the vomeronasal organ contained all the sugar residues investigated, whereas glycoconjugates in the mucociliary complex of the olfactory mucosa and septal organ contained only N-acetyl-D-glucosamine. Vomeronasal receptor neurons expressed glycoconjugates with terminal -D-galactose and -N-acetyl-D-galactosamine, and N-acetyl-D-glucosamine residues, whereas olfactory and septal receptor neurons expressed glycoconjugates with only N-acetyl-D-glucosamine residues. Secretory granules of glands of the vomeronasal organ contained glycoconjugates with terminal -D-galactose and N-acetyl-D-galactosamine, and N-acetyl-D-glucosamine, whereas those of the Bowman's glands and glands of septal organ contained glycoconjugates with only internal N-acetyl-D-glucosamine residues. The results demonstrate that the glycoconjugates expressed by vomeronasal receptor neurons and glands contain terminal -D-galactose and -N-acetyl-D-galactosamine sugar residues that are not expressed by analogous cells in the olfactory mucosa and septal organ.  相似文献   

18.
Aluminum-induced secretion of both citrate and malate in rye   总被引:5,自引:1,他引:4  
Feng Li  Xiao  Feng Ma  Jian  Matsumoto  Hideaki 《Plant and Soil》2002,242(2):235-243
Aluminum (Al)-resistant mechanisms responsible for Al-induced secretion of organic acids are poorly understood. In this study, we characterized the Al-induced secretion of both citrate and malate from rye (Secale cereale L. cv. King). Secretion of organic acids increased with increasing concentration (10, 30 and 50 M) and duration of Al treatments. Neither phosphorous (P) deficiency up to 15 days nor addition of 50M lanthanum, 50 M lead, 10 M cadmium, or 200 M manganese caused secretion of organic acids, suggesting that this secretion was a specific response to Al stress. Aluminum activated citrate synthase, the main enzyme for the synthesis of citrate, but its activation occurred only in the root tip. The elongation of roots of an Al-sensitive cultivar of wheat (Tritium aestivum L. cv. Scout 66) was not inhibited by 50 M Al in the presence of externally applied 50 M citrate or 400 M malate. The secretion of citrate and malate from intact rye roots exposed to 50 M Al corresponded to 31.3 ± 1.7 M and 11.5 ± 2.5 M, respectively, in the rhizosphere based on an assumption of a 2 mm thick unstirred layer around root tips. This result indicated that Al-resistance in rye was achieved by the Al-induced synthesis of citrate in root apices followed by Al-induced specific secretion of citrate from root tips.  相似文献   

19.
Summary Pituitary glands from juvenile (pre-pubertal) and adult male and female rhesus monkeys were examined following immunocytochemical staining with antisera to the beta subunits of ovine luteinizing hormone (LH) and of human thyroid stimulating hormone (TSH). The LH antiserum reacts with a cell that is PAS-positive, occurs singly and is randomly distributed throughout the pars distalis. The diameter of these cells is approximately 11.5 m. They do not seem to vary in number in either juveniles (pre-pubertals) or adults, or in males or females. There appears to be fewer LH cells in the pituitary glands of pregnant and lactating females. In addition to staining cells in the pars distalis, the antiserum also reacts with a population of cells located in the pars tuberalis.The cells that stain with the anti-TSH serum are confined primarily to the pars distalis. They are approximately 15.8 m in diameter and are generally found in groups or clusters located in the anterior and medial regions of the gland. The TSH cells vary in number from one animal to another; however, this variability is unrelated to the age or the sex of the animals. No demonstrable changes occur in the number of TSH cells during pregnancy or lactation.Supported by NIH General Research Support Grant RR05654The author wishes to express appreciation to the Hormone Distribution Program of NIAMDD for the preparations of ovine FSH, TSH and human TSH, and to Drs. H. Papkoff for the ovine LH and LH, L. Reichert for the human FSH, J. Vaitukaitis for the anti-human TSH, and L.A. Sternberger for the PAP complex  相似文献   

20.
Three structural classes of (13)--d-glucans are encountered in some important soil-dwelling, plant-associated or human pathogenic bacteria. Linear (13)--glucans and side-chain-branched (13,12)--glucans are major constituents of capsular materials, with roles in bacterial aggregation, virulence and carbohydrate storage. Cyclic (13,16)--glucans are predominantly periplasmic, serving in osmotic adaptation. Curdlan, the linear (13)--glucan from Agrobacterium, has unique rheological and thermal gelling properties, with applications in the food industry and other sectors. This review includes information on the structure, properties and molecular genetics of the bacterial (13)--glucans, together with an overview of the physiology and biotechnology of curdlan production and applications of this biopolymer and its derivatives.  相似文献   

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